Carl trettin



C. TRETTIN.

vROTARY CONVERTER.

Arrucmou msu lun: 1. m5; ncnzwzp nov. 1.19m.

1,309,001-, Patented July s, 1919.

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UNITED STATES PATENT OFFICE.

CARL TRETTIN,OFQBERLINaGEBMANY, IASS'JGrNOIEt T0 SIEMENS-SCHUKERT WERKEG. M.-B. `'I-I., OF B EJBLIII, v GERMANY, A CORPORATION OIIEy GERMANY.

ROTARY., ooivvl'iirrnitl Specification of Letters Patent. Patented J uly8, 1919.

Appiicanon mea June 7, 1915, serial nasasea;

To all whom t may concern."

Be it known that I, .CARL TRnrriN, a German citizen, and resident xofBerlin, Gerhave invented kcertain new and useful Renewed November 7,1918. Serial No. 261,554.

converter with anl adjustable commutating pole, Fig. 4: is adiagrammatic view of a modification.

Herein a indicates the main field of the this case the motor winding ismounted 1n many, Improvements in Rotary Converters, of o converter, Z)the motor field and c the genwhich the following is a specification,erator field, the armature being assumed to This invention relates torotary converters 10ml@ in direct/i011 21S DdCted by lh@ 111 for.converting continuous current of one row. The two fields 7) and c arerelatively Voltage into continuous current of another displaced t0 eachother as @an be Seen {10111 voltage, and consists in brief in providingthe dmWlngi @Wording t0 the above men 65 a Converter of this kind withproper comtioned displacement of the brushes. If the imitating poles andproperly displacing the T10-.10mi lOSSeS Of the 1110'001." Side areDegbrushes of one commutator to those of the llglbly Small, theTGSUltilig armature field 6l other for .improving the commutation. isobtained by adding the fields c and b. By

In rotary converters of the class specified the displacement of thebrushes of one comthe armature reactions as Well as the remutator tothose of the other two commutatactance voltages of thecoils'duringcommuing ZOIIGS Will be Obtained Which are Sepatation Willapproximately compensate each rated in space and which may be controlledother, if certain conditions are'fulfihed. independently from each otherby especial FOI` compensating the armature reactions, commutatingfields. The strength of the rethe condition is thai-,rho 11o-load lossesof quired commutating field is dependent on themotor side ofthe"convertery are sufiithe one hand upon the angle of displacecicntlysmall, and for compensating Said ment, as shown in Fig. l, and on theother reactance voltages it is necessary that the hand ilponthe strengthof the armature magnetic stray lines which are concatenated Current. Thecommutating fields therefore with only one ofthe windings 'can bonorrmay either be excited by the main current lected. It is thereforeonlyi'possibleto obitself or by a current which is proportionate tain aAgood commutation without the emto the same. In the present example,where ployment of Special commumi-,ing 'poleaq if the no-load losses ofthe motor are neglected, both these conditions are fulfilled. In mathecommutating fields required for those 8 5 chineg carrying great loadsthe effects which commutating yZones which are associated to l are dueto armature reaction and reactance Gell other are of equal dimensionsbut of voltage can no more be neglected in order' to oppositedirections. These commutating secure good commutation. If in suc-hcasesv fields according to my invention now are commutating poles "ofthe normal construcgenerated by the commutating pole shown tion 'areemployed, these poles would cerin Figs. 2 and 3. This pole consists of atainlyfavorably actupon'the short-circuit double-shanked Ueshaped ironbody e, and windingof the one side'of the converter, the carries thecommutating coils f upon its commutating conditions of the other side,Shanks. As thev commutating field needs to however, would be krenderedmore unfavorbe only of small strength as a rule a small able. This isdue tothe fact that the short# iron width of the commutating pole willbe circuit coils in 4the armaturek ofthe consufficient, such asindicated in Fig. The verter arey arranged one above the other and,commutating pole now is adapted to be adthat the reactance voltages areof adirection justed by means of a pivot screw bolt g or opposite toeach other. the like at the center of its yoke and is set 10o In orderto avoid these disadvantages, acaccording to the temporary brushposition cording to my invention the oommutating in such a manner thatthe two shankswill zones of the two sides of the converter are bepositioned above the appertaining comdisplaoed relatively to each otherand espemutating zones. cial commutating pole constructions are pro- Ifthe no-load losses of the motor side are vided for these two commutatingzones. of such an amount that they cannot be neg- Figure 1 is adiagrammatic view showing lected, the construction shown in Fig. 4 willthe fields of a rotary converter according to enable to use one and thesame commutating the present invention, Figs. 2 and 3 show field forobtaining good commutation. In the combinationof the windings of thesame the usual manner in the upper part of the slots of the armature, inorder to render its leakage small as compared with that of the generatorwinding. Furthermore the converter may be mechanically coupled with anauxiliary motor /L serving to furnish the noload losses of the motorside. Such an auxiliary motor possesses the further advantage that itmay be used for starting the converter, t-hus dispensing` with anespecial starting device for the motor side which is especiallydesirable in high voltage power stations.

Having thus described my i intention I claim as new and desire to secureby Letters Patent of the Uni ed States l. A rotary converter forconverting continuous current of one voltage into continuous current oi'another voltage, comprising an armature having' two windings, acommutator connected to each of said windings, a set of brushes on eachot said commutators, said sets of brushes being displaced relatively toeach other, main poles, and comunitating poles intermediate between saidmain poles for generating distinct cominutating Zones for each of saidwindings.

2. A rotary converter for converting continuous current of one voltageinto continuous current of another voltage, coniprising an armaturehaving two windings, a commutator connected to each of said windings, aset of brushes on each of said commutators, said sets o'l brushes beingdisplaced relatively to each other, main poles, and double-shanledU-shaped commutating poles intermediate between said main poles, theShanks of said commutating poles being positioned in the commutatingzone ot' each of said windings.

3. A rotary converter for converting continuous current of one voltageinto continuous current of another voltage, comprising an armaturehaving two windings, a commutator connected to each 0i said windings, aset of brushes on each of said commutators, said sets ot' brushes beingdisplaced relatively to each other, main poles, and double-shankedU-shaped commutating poles intern'iediate between said main poles, theshanks of said coniniutating poles being positioned in the commutatingzone of each of said windings, said commutating poles being mounted topermit rotation for adjusting the same relatively to said commutatingzones.

4l. A rotary converter for converting continuous current of one voltageinto con- Copies of this patent may be obtained for ve cents each, byaddressing the tinuous current of another voltage, comprising anarmature having two windings, a cominutator connected to each of saidwindings, a settL of brushes on each of said commutators, said sets ofbrushes being displaced relatively to each other, main poles, andcommutating poles intermediate between said main poles for generatingdistinct conimutating zones for each of said windings, and an auxiliarymotor mechanically coupled with said converter for com ensating theno-load losses of the motor sic e of said converter, whereby saidauxiliary motor may be used for starting said converter.

5. A rotary converter for converting continuous current of one voltageinto continuous current of another voltage, comprising an armaturehaving two windings, a commutator connected to each of said windings, aset of brushes on each of said commutators, said sets of brushes beingdisplaced relatively to each other, main poles, and double-shankedU-shaped commutating poles intermediate between said main poles, theshanls of said commutating poles being positioned in said commutatingzones, and an auxiliary motor mechanically coupled with said converterfor compensating the no-load losses of the motor side of said converter,whereby said auxiliary motor may be used for starting said converter.

G. A rotary converter for converting continuous current of one voltageinto continuous current of another voltage, comprising an armaturehaving two windings, a commutator connected to each of said windings, aset of brushes on each of said commutators, said sets of brushes beingdisplaced relatively to each other, main poles, and double-shankedU-shaped commutating poles intermediate between said main poles, theShanks of said commutating poles being positioned in the commutatingzone of each of said windings, said connnutating poles being mounted ona pivot so as to be adjustable relatively to said commutating Zones,and` an auxiliary motor mechanically coupled with said converter forcompensating the no-load losses of the motor side of said converter,whereby said auxiliary motor may be used for starting said converter.

In testimony whereof I have hereunto set my signature in the presence oftwo subscribing witnesses.

CARL TRETTIN. lVitnesses VOLDEMAR HAUPT, HENRY HASPER.

Commissioner of Patents,

Washington, D. C.

